The long-term goal of this research is the development of a rapid DNA sequencing method based on scanning tunneling and atomic force microscopy and newly developed microscope tips. Our approach attempts to overcome three serious limitations of current sequencing methods-the need to sub- clone DNA in kilobase fragments, the restriction of chemical sequencing methods to roughly kilobase lengths of DNA, and the difficulties inherent in sequencing long repetitive sequences. To overcome these serious obstacles to rapid sequencing, we propose to (1) develop methods for clamping long single strands of DNA to substrates so they can be followed over 10-100 kilobases, and (2) devise novel microscope tips designed to recognize the adsorption spectra of individual purines and pyrimidines. Our proposed new methods clamp the DNA to substrates using well-understood physical and chemical principles and recent advances in tunneling microscopy. The proposed methods do not depend on atomic scale resolution, and in principle accelerate the sequencing speed by many orders of magnitude.